1996 dodge ram truck does not run

My 96 ram 5.9 does not run ive changed the crankshaft
sensor camshaft sensor (otherwise known as a pick up
sensor or whatever thats not what i know it as) distributor
cap intake manifold gaskets changed the oil oil filter checked
and repaired the fuel line (it is not gas) pressure is just fine
(however could it be the injectors?)       
changed the ignition coil  and added good gas as well as
treatment (intake manifold gaskets were replaced because of
water in the oil) (not the head gasket it is fixed) throttle body
does let gas just leak in when i pour gas into it and it does
not start with starting fluid either as i probably should have
mentioned already ( it only cranks ) its not the battery either  
its a commercial truck battery being used which started the
truck just fine 3 times first time within very few seconds as
well as the other two tries but the fourth time after a few
hours after it started up i  cranked it it roughishly started
and then made a whooshing sound after that it hasnt started
up it has gas and started up fine other than the fact that the
rpm gauge had a hard time leveling out to 1 going past
multiple times but not under 1 on the rpm gauge  
I will admit i got the truck from a dumbass in high school
who actually cut the center out of a mediumly expensive
while still custom rim just because he couldnt get one lugnut
off so i can see problems occuring with it like vacum lines
which were either not hooked up right or at all even which i
fixed the right and the left lines ive heard about a method as
well rhat you keep your foot fully on the gas while you try to
crank it for 20-30 seconds but it doesnt work  so after
reading this and you have any ideas of what it could be
please let me know ive done everything i can to get my baby
back on the road but ive had no luck so please if you have
any idea please help me out